Steel frame thresher screen



I w. A. HOLTZMAN STEEL FRAME THRESHER SCREEN April 25, 1944.

2 Sheets-Sheet 1 Filed Oct. 22, 1941 April 25, 1944- w. A. HOLTZMAN 2,347,480

STEEL FRAME THRESHER SCREEN Filed Oct. 22, 1941 v ZShegts-Sheet 2 Patented Apr. 25, 1944 STEEL FRAME THRESHER SCREEN William A. Holtzman, Peoria, 111., assignor to Hart-Carter Company, Peoria, 111., a corporation of Delaware Application October 22, 1941, Serial No. 416,036

4 Claims. (Cl. 189-36) This invention relates to thresher screen frames such as are employed in grain threshers or combined harvester threshers.

Heretofore the frames of such screens have been commonly made of wood because this material, when of good quality, made a satisfactory frame for ordinary uses and could be readily repaired in the field by ordinary tools in the hands of farm mechanics. However, the grow ing use of combined harvester thresher with greatly increased harvester speeds and the stresses and strain of rapid transportation over rough ground, together with increased difficulties in getting proper quality lumber for frames, has indicated the need for stronger, stiffer and better-fitting thresher screens.

The particular object of this invention is to provide a structure for steel frame thresher screens which are strong and light and may be made up in a wide variety of accurate sizes from the same tools and which may be quickly and easily repaired by farm mechanics with ordinary tools.

Other objects and benefits will be disclosed in the following descriptions and drawings, in which:

Fig. 1 is a top plan view showing my new steel frame thresher screen;

Fig. 2 is a cross sectional view through an end section frame, as it would appear on the section lines 22 of Fig. 1;

Fig. 3 is another similar cross sectional view as it would appear on the section lines 33 of Fig. 1;

Fig, 4 is an enlarged perspective view of a steel reinforcement member, as will later be explained;

Fig. 5 is a broken, cross sectional, elevational view of the side frame showing the cross wires mounted in support notches, as would appear on the section line 5-5 of Fig. 1;

Fig. 6 is a broken side elevational view, partly in section, showing the center frame member and its mounting on the end members of the frame;

Fig. 7 i a cross sectional, elevational view of the center member showing a cross wire with adjustment crank, as would appear on the sectien line 1'l of Fig. l;

Fig. 8 is a broken underneath plan view of the frame corner with partial assembly shown in dotted outline, as will later be explained;

Fig. 9 is an upright section of the frame corner, as would appear on the line 9-9 of Fig. 8; and

Fig. 10 is a developed plan view of the end frame member, later to be explained.

Fig. 11 is a bottom plan view of the rail I6 as shown in Fig. 8 with flap extended; and

Fig 12 i an elevational view of the rail 16 as shown in Fig. 11.

Now referring to the drawings, I designate the side rails of the thresher screen by the numeral I5. The end rails l6 are attached to the side rails with a corner reinforcement member H, as will later be explained in greater detail.

Referring to Figs. '2 and 3, it will be observed that the end rail H5 is made in a general rectangular tubular section with top extending flanges Hid and Hi?) extending inwardly therefrom. It will be understood that the rails l5 are made in similar section, having inwardly extending flanges I50, and lfab. However, the side rails l5 have circular indentations I511, embossed downwardly in the top of the flanges to form pivot sockets for the slat wires l8, as clearly shown. Any'suitable means, such as a plate, may be placed over these pivot sockets to prevent the ends of the wires Hi from being displaced therefrom under normal operating conditions. Extending crosswise in the center of the frame is a central rail made up of two sections 20 and 2!, which may be of wood or other suitable material joined together by any suitable securing elements 22, such as screws, bolts, or the like as clearly shown in Fig. 7. This central rail may be fastened to the frame by rivets 23 or the like extending through the sections 16a and lfib of the end rails, as clearly shown in Fig. 6. It will be appreciated that these rivets merely hold the bottom member 2|, and the top section 20 may be removed with an ordinary screw driver by removing the securing elements 22, whereupon the cross wires i 8, having central cranks l8c, may be removed for repairs or replacements of the slats l9.

Referring to Figs. 4, 8, 9 and 10, it will be observed that th steel corner reinforcement member i! is made with square corners in accurate square conformation. This reinforcement section is inserted in the hollow corner and, as will be observed by a study of Figs. 4, 8, 9 and 10, the square corner section permits the rails l5 and IE to be assembled with accurate square corners and with the holes [5h and lfih (Fig. 10') in alignment where they may be securely held by the through rivets 25 (Figs. 8 and 9). It will be observed that the ends of the rails I5 and iii are arranged to abut and overlap each other to effect a stiff, interlocked corner. I show in Fig. 10 the flat, developed plan view of the end rail l6, and I wish to explain that the entire end of the rail l6, including the holes l6h, is cut with a die to effect accurate corner configuration of the rail. The side rails l5 have square ends and therefore holes corresponding with l6h are punched in accurate relationship with the square ends. By observing Figs. 8, 9 and 10 it will be seen how the rails are interconnected with the flat section if of the rail (6 extended as shown in dotted outline in Figs. 8 and 9. When assembled and riveted by the rivets 24 in accurate position the section l 6 is folded around and beneath the rail l5, and the entire assembly spot-welded together, as indicated at spots marked W, Fig. 8.

An analysis of this structure will show that the stiffener members I! contribute largely to the stiffness of the assembly because they are inserted at the point of greatest strain, namely, the corners. However, in some installations, particularly with small screens, the stiffener member ll may be left out, thus sacrificing strength for lightness.

It will be further observed that my rails are formed by bending operations which may be performed with any length of rail desired. Therefore, in order to make different size screens it is necessary to adjust only the length of the rails, and thus screens of various sizes may be con structed with the same set of tools.

It will also be observed that the cross-wire indentations [5n in the side rails I5 effectively prevent shifting of the extended flanges Wu and I512, especially when these flanges are spot-welded together. Inwardly extending flanges l5a--l5b and Ito-45b are important elements in my novel structure because they permit not only effective fastening together of the rails and the mounting of the cross wires I8 of the slats H], but by their very nature permit field repairs with ordinary tools in the hands of a farm mechanic.

It will be appreciated that in high-speed, combined harvester threshers, the screens must fit accurately and firmly in position in order to effectively utilize the air blast and withstand severe service strains.

The application of my screen frame to a thresher screen or sieve, is set forth and claimed in my copending application on Steel frame thresher screen, Ser. No. 443,919, filed May 21, 1942. My said application sets forth also more in detail the slat adjusting mechanism generally referred to above.

It will be evident from the foregoing description that the side and end rail sections l5 and l B are initially formed substantially of rectangular cross section, and are assembled with their respective flanges I511, I5b and Mia, lBb extending inwardly of the frame, generally as illustrated in Fig. 8. The reinforcing member I! has the arms thereof fitted into said rectangular rail sections, or the latter are formed therearound, and the rails are thus assembled with the rail l5 arranged with its extreme end in abutting endwise contact with the inside wall of the rectangular section of the end rail H5, in which relation the flanges I 5a, I5b and [6a, lSb are interlapped, as shown in Figs. 8 and 9. In this relation the holes in the flanges of the rails l5 and I6 are in alignment, and the rivets 24 may be inserted therein and secure these flanges and the rails together. The

flap l6 which initially projects outward in a horizontal direction as shown in dotted lines in Fig. 9, is then wrapped around the rail l5, as shown in full lines therein, throughout the outer sides and bottom of the side rail section, to which it is secured, as by spot welding. Additional welds may be used to secure the other parts in their assembled relation, as indicated at W in Fig. 8.

Having thus described my invention, I now claim as new:

1. In a steel thresher screen, side and end rails formed in hollow rectangular sections with inwardly extending flanges, the rails having rivet holes near their ends through the flanges, the end rails being formed with folding flaps on the top flanges, the inside ends of the side rails being formed and arranged for abutting endwise contacts with the inside walls of the rectangular section of the end rails, the flanges bein interlapped with the rivet holes in alignment when in exactly square sized relationship, rivets through the rivet holes, the flaps of the end rails being folded around the outside edges and bottoms of the rectangular sections of the side rails, and fastening means to hold the parts in square relationship.

2. In a steel thresher screen, side and end rails formed in hollow rectangular sections with inwardly extending flanges, the rails having rivet holes near their ends through the flanges, the end rails being formed with folding flaps on the top flanges, right angle corner reinforcement members fitting inside the ends of the rectangular rail sections, the inside ends of the side rails being formed and arranged for abutting endwise contacts with the inside walls of the rectangular section of the end rails, the flanges being interlapped with the rivet holes in alignment when in exactly square sized relationship, rivets through-the rivet holes, the flaps of the end rails being folded around the outside edges and bottoms of the rectangular sections of the side rails, and spot-Welding means to hold the parts in square relationship.

3. In a steel thresher screen, side and end rails formed in hollow rectangular sections with inwardly extending flanges, the rails having rivet holes near their ends through the flanges, the end rails being formed with folding flaps on the top flanges, the flanges being interlapped with the rivet holes in alignment when in exactly square sized relationship, and rivets through the rivet holes, the flaps of the end rails being folded around the outside edges and bottoms of the rectangular sections of the side rails.

4. In a steel thresher screen, side and end rails formed in hollow rectangular sections with inwardly extending flanges, the rails having rivet holes near their ends through the flanges, the end rails being formed with folding flaps on the top flanges, right angle corner reinforcement members fitting inside the ends of the rectangular rail sections, the flanges being interlapped with the rivet holes in alignment when in exactly square sized relationship, and rivets through the rivet holes, the flaps of the end rails being folded around the outside edges and bottoms of the rectangular sections of the side rails.

WILLIAM A. HOLTZMAN. 

